The present invention relates to a silicone composition which can be cured by both moisture-curing and photocuring mechanisms.
Silicone as a soft cured material is used in various industrial fields requiring impact resistance, vibration resistance and thermal stress resistance, while making the most of its highly elastic performance, and thus it is a material of a high utility value. However, the conventional one-pack type silicone requires a considerable time for complete curing because it undergoes a condensation reaction in the presence of moisture to cure. To avoid this inconvenience, a silicone which cures upon exposure to light has recently been developed. For example, a silanol terminated organopolysiloxane is treated with an aminoalkoxysilane to replace the end with amino group, and glycidyl (meth)acrylate is added thereto, to render the siloxane photocurable (see Japanese Patent Laid Open No. 55-112262A). However, this reaction is a reaction between limited functional groups, and since alkoxysilane is used in the addition reaction, hydrolyzable groups are diminished and hence the moisture-curability is deteriorated. In Japanese Patent Laid Open No. 1-318028A, a photo- and moisture-curable composition is obtained by isocyanate linkage of a compound having acryl and alkoxysilyl-groups and a terminal hydroxyl modified silicone oil. But this composition also involves problems such as, for example, high viscosity and very poor handling property.
It is the object of the present invention to overcome such drawbacks of the prior art and provide a silicone composition easy to manufacture and having superior photo- and moisture-curability.